Atmosphere and Climate Studies

Cloud Fraction and Cloud Cover

Cloud Fraction is derived from the cloud cover product generated using the radiance and reflectance measurements from the thermal infrared and visible channels respectively along with water vapour channel from Very High Resolution Radiometer (VHRR) onboard Indian Geo-Stationary Satellite INSAT-3D. The approach followed is to generate a clear sky composite using visible and thermal channels reflectance and radiance measurements respectively and then applying thresholds to arrive at detection of a cloudy pixel.

A pixel is defined as cloudy if it satisfies the above mentioned criteria in all three channels used. Cloud fraction products are being made available at half-hourly intervals (i.e. 48 products per day). This methodology will be applied to generate cloud fraction from INSAT-3D starting from year 2013 to present, and eventually for INSAT-3DR.

Daily Cloud fraction and cloud cover data at 10KM , 25Km grid from 2017--2018 is hosted on Bhuvan-Cloud Fraction and Cloud Cover.

Select NICES Project – Atmospheric and Climate Sciences –Daily Cloud fraction and cloud cover, List and view the data of the selected time period. Technical Document(hyper link :Cloud Fraction and Cloud Cover)